We'd like to discuss the draft below that introduces extensions for Atom
and AtomPub to deal with hierarchies of feeds and the programmatic
creation and removal of AtomPub Collections.

This draft defines a mechanism for identifying hierarchical
master-detail relations among data feeds so that consumer applications
can perform standard AtomPub operations on them. A hierarchical
master-detail relation of an Entry to a Feed implies the detail Feed is
created when the master Entry is created and the Feed is removed when
the Entry is removed. The Entry is called the "master entry" and the
Feed is called "detail feed". This relationship allows a client to use
AtomPub to create a new Collection by posting an Entry to an existing
Collection.